This historical tornado data archive was compiled under a grant by the Nuclear Regulatory Commission during the 1970s, and has been maintained since then by the National Severe Storms Forecast ... Center (now by the Storm Prediction Center). Raw coded data is available only for 1950 through 1995. Other tornado information is compiled from Storm Data. Raw severe weather data from 1996 onward will be archived along with all other types of U.S. weather data at the National Climatic Data Center (NCDC) in Asheville, NC.

The United States hail data and convective wind data cover the years 1955-1996. Severe weather data after 1995 is archived at NCDC.